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Found 6414 publications

Domain decomposition method with an interface preconditioner for frictionless contact problem

Lotfi Abdelhakim

Publication Name: Aip Conference Proceedings

Publication Date: 2008-10-22

Volume: 1048

Issue: Unknown

Page Range: 359-363

Description:

The present paper is concerned with the frictionless bilateral or unilateral contact problem between two elastic bodies. An algorithm is introduced to solve the resulting finite element system by a non-overlapping domain decomposition method. This technique enable us to transform the solution of the global problem to the solutions of the elasticity equations for each body separately and the solution of the Schur complement problem on the contact surface. The main goal of this work is the construction of the interface preconditioner for the Schur complement problem. The solution is obtained by using a successive approximation method. Finally, some numerical results of the proposed method are given. © 2008 American Institute of Physics.

Open Access: Yes

DOI: 10.1063/1.2990933

Egysejt-fehérje előállítása állati takarmányozáshoz fermentációs biotechnológiával

Renato Kalocsai Mukhtar H. Ahmed Judit Molnár Dávid Vasas Tamás Szakál

Publication Name: Elelmiszervizsgalati Kozlemenyek

Publication Date: 2022-06-30

Volume: 68

Issue: 2

Page Range: 3888-3895

Description:

No description provided

Open Access: Yes

DOI: 10.52091/EVIK-2022/2-3-HUN

On the development of signatures for Artificial Intelligence applications

Claudiu Radu Pozna Péter Földesi Radu Emil Precup Laszlo T. Koczy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2014-09-04

Volume: Unknown

Issue: Unknown

Page Range: 1304-1310

Description:

This paper illustrates developments of signatures for Artificial Intelligence (AI) applications. Since the signatures are data structures with efficient results in modeling of fuzzy inference systems and of uncertain expert systems, the paper starts with the analysis of the data structures used in AI applications from the knowledge representation and manipulation point of view. An overview on the signatures, on the operators on signatures and on classes of signatures is next given. Using the proto fuzzy inference system, these operators are applied in a new application of fuzzy inference system modeled by means of signatures and of classes of signatures.

Open Access: Yes

DOI: 10.1109/FUZZ-IEEE.2014.6891636

The Role and Impact of Digital Transformation in the Development of Professional Teachers' Methodological Culture

Laszlo Kadocsa Gyula Gubán Levente Juhász Gyorgy Molnar

Publication Name: Cando EPE 2024 Proceedings IEEE 7th International Conference and Workshop Obuda on Electrical and Power Engineering

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 171-178

Description:

Today's professional teacher training system includes both professional and pedagogical preparation, the main aim of this training being to further develop the methodological part of the teacher training. In the last three decades, the institutional system and the content of Hungarian VET have been characterised by constant change, significantly influenced by the series of decisions and recommendations on VET in the EU. While continuous structural and content change has updated the VET infrastructure, and modern curricula have been developed, this modernisation has been accompanied by only modest digital and methodological changes. While all the development programmes implemented have made efforts to improve the methodological knowledge of vocational teachers, the results have been less visible in practice. Research on teaching methods and the methodological culture of professional teachers in vocational subjects has been scarcely reported in the professional press. At the same time, the learning environment has changed dramatically over the last decade, and the need for digital education has significantly altered the expectations of teachers in terms of teaching methods. The digital transformation of education is not a digitally-enhanced version of traditional teaching methods, but a new learning environment in terms of approach, requirements, methodology and assessment systems. In our study we want to present an empirical research and its results, as well as new directions for development, which aimed at partially overcoming this methodological gap at the University of Dunaújváros, In this context, we describe in detail the study that was carried out by means of a questionnaire survey and focus group interviews among engineering and vocational students of the institution in 2014 and 2024.

Open Access: Yes

DOI: 10.1109/CANDO-EPE65072.2024.10772873

Training Capsule Networks with Various Parameters

Áron Ballagi Janos Hollosi

Publication Name: Saci 2019 IEEE 13th International Symposium on Applied Computational Intelligence and Informatics Proceedings

Publication Date: 2019-05-01

Volume: Unknown

Issue: Unknown

Page Range: 191-196

Description:

Nowadays convolutional neural networks (CNNs) have produced the state-of-The-Art performance in image classification and segmentation tasks. The efficiency of the neural networks is one of the bests when the testing samples are close to the training data. Nevertheless, if we make some transformation on the dataset, the performance of the convolutional neural network reduced. Recently, capsule networks (CapsNet) have been introduced to solve some of the problems of neural networks. In this paper we examine the effectiveness of three different capsule based neural networks, and compare the performance when the parameters of the dynamic routing algorithm and the squashing function are modified.

Open Access: Yes

DOI: 10.1109/SACI46893.2019.9111574

The effect of mold temperature on chemical foaming of injection molded recycled polyethylene-terephthalate

Ferenc Ronkay Bela Molnar Gabor Dogossy

Publication Name: Thermochimica Acta

Publication Date: 2017-05-10

Volume: 651

Issue: Unknown

Page Range: 65-72

Description:

Foam injection molded samples were produced from recycled polyethylene-terephthalate using endothermic and exothermic foaming agents at different mold temperatures. The foam structure was analyzed by computer tomography and optical microscopy. The morphological properties of samples were analyzed by differential scanning calorimetry, using the three-phase model. Viscosities of the melts were changed during processing by endothermic and exothermic foaming agents, and as a result different foam structures were formed. Relationships between mold temperature and porosity were found. Morphologies of the samples made with different foaming agents were different, also due to the different cooling rates caused by the endothermic and exothermic foaming reactions.

Open Access: Yes

DOI: 10.1016/j.tca.2017.02.013

The number of independent elements in heat transmission matrices

Ádám Bácsi

Publication Name: International Journal of Thermal Sciences

Publication Date: 2019-04-01

Volume: 138

Issue: Unknown

Page Range: 496-503

Description:

Unsteady heat transfer processes between a heat source and the environment are completely described by the frequency-dependent heat transmission matrix within linear response theory. The 2×2 matrix characterizes the linear relation between the temperature and the heat transfer rate at the heat source and the environment sides of the system. In generic case, the heat transmission matrix has four independent complex entries. The number of independent elements may be reduced in the presence of certain properties or symmetries of the system. In the present paper, it is shown how the microscopic, governing equations influence whether the heat transmission matrix has a determinant of unity. A determinant fixed to one allows only three independent elements of the matrix. In the presence of a spatial symmetry under which the roles of the heat source and the environment are changed, the number of independent entries is reduced to two. The two independent elements may be formulated in terms of an effective thermal resistance and an effective heat capacity. In the case of a heat conducting wall, the effective values are independent of the frequency and equal to the static thermal resistance and heat capacity of the system. For generic symmetric systems, however, the effective thermal resistance and heat capacity may exhibit significant frequency dependence. The frequency dependence is numerically studied in the example of the heat conduction between two parallel pipes.

Open Access: Yes

DOI: 10.1016/j.ijthermalsci.2019.01.005

Social Impact Assessment in Urban Security Management Projects: A Case Study from Pakistan

Dávid Fekete Eniko Varga Usman Ghani Peter Toth Zoltán Baracskai

Publication Name: Academic Journal of Interdisciplinary Studies

Publication Date: 2024-01-01

Volume: 13

Issue: 1

Page Range: 33-56

Description:

Public safety and security management projects are devised to reduce crime, fear and calamities by prevailing law and order to reduce the harm in society. In a certain context, social impact assessment is a novel way to reveal the extent of effectiveness for these projects. This case study presents an Expert System based methodology regarding social impact assessment for two urban security management projects in Pakistan. An Expert System, DoctuS is employed as a tool to build a rule-based model tool using social impact attributes (as variables) from literature and expert knowledge (Author’s own insight as being involved in projects). Case-based reasoning (CBR) method is employed for the measurement of the impact of urban security management KPIs (Key Performance Indicators) in the two case projects. The empirical findings in this case study approaches the impact assessment by quantitative analysis of crime rates in JMP statistical package and Qualitative Expert knowledge-based model in DoctuS. Thereby, the study evaluates the pre and post ante project situations in order to assess the project’s effectiveness and impact on improved urban safety and security. In the first step, the projects are briefly described, followed by the crime rate analysis under the project jurisdictions and rules between attributes are defined. The second step defines the qualitative rule-based model along with the two cases described, and validated in DoctuS tool. Some attributes and rules have changed, and a new concise model is presented. The Expert System compares the project cases and evaluates the social impact assessment based on the defined KPIs. The Expert system validation presents a novel model for social impact assessment of subject urban security management projects. We propose this methodology and model as useful in investigating social impact assessment of projects specifically dealing with urban safety and security management. However, the generalizability of the findings of this case-study based articles need more sophisticated tests as recommendation for the extension to this study

Open Access: Yes

DOI: 10.36941/ajis-2024-0004

Efficient Layer-by-Layer Processed Small-Molecule Donor/Polymer Acceptor Solar Cells: Morphology-Dependent Charge-Transfer Mechanisms

Gusztáv Fekete Hai Qiao Wang Shu Xu István Bíró Xingyu Liu Beining Wang Zhongle Chen Yuxuan Wang Chenghuan Chen

Publication Name: ACS Photonics

Publication Date: 2026-01-21

Volume: 13

Issue: 2

Page Range: 424-432

Description:

Small-molecule donor:polymer acceptor (SMD:PA) organic solar cells have garnered attention due to their excellent active layer stability, yet their efficiency remains significantly lower than other OSC types. This study addresses the challenge of morphology control in SMD:PA systems via a layer-by-layer (LBL) process to optimize the donor–acceptor interpenetrating network. Using small-molecule donor B1 and polymer acceptor PY-IT with chloroform as a universal solvent, we systematically investigated the impact of LBL processing on the active layer morphology and device performance. The inverted LBL device (ITO/ZnO/PY-IT/B1/MoO3/Ag) achieved a power conversion efficiency of 8.6%, significantly outperforming the bulk heterojunction devices (inverted 2.91% and normal 6.11%) and previously reported LBL SMD:PA cells (1.12%). Static and femtosecond transient absorption spectra, time-resolved photoluminescence, and grazing incidence X-ray diffraction analyses revealed that the LBL and nonorthogonal solvent strategy facilitated effective B1 infiltration into the PY-IT layer, forming an optimized active layer with refined phase separation and improved donor/acceptor interfaces, thus resulting in enhanced exciton dissociation and charge transport while reducing recombination losses. This work validates the feasibility of LBL processing for high-efficiency SMD:PA OSCs, offering a novel strategy to overcome the efficiency limitations of this class of OSCs.

Open Access: Yes

DOI: 10.1021/acsphotonics.5c02041